I don't believe a scanner uses a lens? Color reproduction is going
to be more dependent on how correctly profiled (calibrated) the
system is, bit depth and the sensor array of the scanner and also
how finely the stepper motor moves at each increment as it moves
across the image being scanned. Please correct me if I'm wrong on
this.
Most modern lenses are corrected for chromatic abberations across
the visible spectrum. From what I know of lens design, it's always
a compromise trying to get all wavlengths of light to focus
identically at the same distance from lens to film plane. My guess
is that once you hit a certain price plateau, you are going to see
little difference from one brand to the other. The most marked
differences will be due to camera focus and internal processing (if
any) and variations in sensor array resolution.
I'm pretty sure that the Goerz lenses are now in the collector's
realm although they are still used by some large format photographers.
RA Friedman, Philadelphia
http://rafriedman.com
________________________________
From: Association for Recorded Sound Discussion List on behalf of
Malcolm Smith
Sent: Thu 8/14/2008 11:31 AM
To: ARSCLIST@xxxxxxxxxxxxxxxx
Subject: Re: [ARSCLIST] Large-format scanner redux
A couple of thoughts with respect to copying flat originals. There is
a reference to distortion. This common problem is caused by lenses
not being symmetrical (front elements the same as the rear elements).
There are lenses designed for producing color separations. They are
known as Apocromats. They are corrected for three colors instead of
two. If there is any way to use them, they can probably be found
second hand at bargain prices. They were once very expensive. One
name to look for would Artar produced by Goertz American Optics. The
images these lenses produce from color originals are very much better
than those produced with regular lenses.
Malcolm Smith.